TECHNICAL FIELD
[0001] This application relates to communications technologies, and in particular, to a
data communication method, a network device, and a terminal device.
BACKGROUND
[0002] A multiple-input multiple-output (Multiple-Input Multiple-Output, MIMO) technology
means that a plurality of transmit antennas and receive antennas are used at each
of a transmit end and a receive end, so that a communication signal is transmitted
and received through a plurality of antennas at the transmit end and the receive end,
to improve communication quality. In the MIMO technology, spatial resources can be
fully utilized, and multiple-input multiple-output is implemented by using a plurality
of antennas. Therefore, a system channel capacity can be increased by times without
increasing spectrum resources and antenna transmit power. The MIMO technology presents
a significant advantage and is considered as a core technology for next-generation
mobile communications.
[0003] However, LTE currently supports only MIMO communication corresponding to one demodulation
reference signal (Demodulation Reference Signal, DMRS) antenna port group (antenna
ports belonging to a same DMRS port group satisfy a QCL relationship). For MIMO communication
corresponding to a plurality of DMRS port groups (antenna ports belonging to different
DMRS port groups do not satisfy a QCL relationship), because joint precoding cannot
be performed on DMRS ports in the groups, there is severe inter-layer interference
between different data flows sent through DMRS ports belonging to different groups.
To reduce inter-layer interference, an interference cancellation receiver is disposed
in a terminal device, but a precondition for supporting the interference cancellation
receiver by the terminal device is that data flows mapped to different transport layers
can be independently decoded; otherwise, interference cannot be canceled. Therefore,
how to independently decode data flows mapped to different transport layers is a technical
problem to be resolved in this application.
[0004] EP3451736A1 describes signaling transmitting and receiving methods.
[0005] US2015049704A1 describes a method for transmitting or receiving a downlink signal.
WO2010098532A1 describes a method for transmitting a transport block.
US2010303034A1 describes dual-layer beam forming in cellular networks.
[0006] CN102158319A describes a method for pre-encoding based on hybrid multiplex demodulation reference
symbols.
SUMMARY
[0008] Embodiments of the invention provide a data communication method, a network device,
and a terminal device, to independently decode data flows mapped to different transport
layers as set forth in the claims.
[0009] According to a first aspect, an embodiment of the invention provides a data communication
method, including:
determining, by a network device, demodulation reference signal DMRS port groups,
where a quantity of the DMRS port groups is greater than or equal to 2; and
communicating, by the network device, data with a terminal device, where the data
is corresponding to a transport block, the transport block is divided into at least
one code block group CBG, and each of the at least one CBG is corresponding to one
DMRS port group and is mapped to a transport layer corresponding to the one DMRS port
group.
[0010] According to the data communication method provided in the first aspect, the network
device communicates the data with the terminal device, where the data is corresponding
to the transport block, the transport block is divided into the at least one code
block group CBG, and each of the at least one CBG is corresponding to one DMRS port
group and is mapped to a transport layer corresponding to the one DMRS port group.
It can be learned that, it is ensured that data flows sent through different DMRS
port groups belong to different CBGs, so that the terminal device can independently
decode a CBG corresponding to each DMRS port group, in other words, can independently
decode data flows mapped to different transport layers, and therefore can support
interference cancellation performed by an interference cancellation receiver.
[0011] In a possible design, that the transport block is divided into at least one CBG includes:
the transport block with an added redundancy check bit is divided into N code blocks
CBs, where N = ┌B / c┐, B represents a total quantity of bits of the transport block with the added redundancy
check bit, C represents a preset value, and ┌ ┐ represents a round-up
operation; and
the N CBs are grouped into CBGs corresponding to the DMRS port groups. In a possible
design, a quantity of CBs included in each CBG is equal to a value calculated based
on the following formula: └(B0 / Bs)× N┘ or ┌(B0 / Bs)× N,where
B0 represents a quantity of bits of data sent through a DMRS port group corresponding
to the CBG, Bs represents a total quantity of bits of data sent through the DMRS port groups, |_
J represents a round-down operation, and ┌ ┐ represents a round-up operation.
[0012] In a possible design, that the transport block is divided into at least one CBG includes:
the transport block is divided into a transport sub-block corresponding to each DMRS
port group; and
each transport sub-block is encoded to obtain a CBG corresponding to the DMRS port
group.
[0013] In a possible design, the method further includes:
sending, by the network device, a notification message to the terminal device, where
the notification message carries configuration information of the DMRS port groups.
[0014] In a possible design, that each of the at least one CBG is mapped to a transport
layer corresponding to the one DMRS port group includes:
a preset quantity of data bits are sequentially extracted in a first preset order
from a data bit sequence included in a CBG corresponding to each DMRS port group,
and serial concatenation is performed on the data bits to obtain a concatenated data
bit sequence; and
the concatenated data bit sequence is mapped to each transport layer according to
a predefined mapping policy.
[0015] According to the invention, the fact that a preset quantity of data bits are sequentially
extracted in a first preset order from a data bit sequence included in a CBG corresponding
to each DMRS port group, and serial concatenation is performed on the data bits to
obtain a concatenated data bit sequence includes:
when extraction is performed m times on the data bit sequence included in the CBG
corresponding to each DMRS port group to extract the entire data bit sequence, serial
concatenation is sequentially performed on a first data bit sequence to an mth data bit sequence to obtain the concatenated data bit sequence, where m is a total
quantity of times of performing extraction on the data bit sequence included in the
CBG corresponding to each DMRS port group, and m is a positive integer greater than
or equal to 2, where
the first data bit sequence is a data bit sequence obtained by sequentially extracting
first Qi data bits in a second preset order from the data bit sequence comprised in
the CBG corresponding to each DMRS port group and performing serial concatenation
on the first Qi data bits, where Qi represents a quantity of data bits extracted from
a data bit sequence included in a CBG corresponding to an ith DMRS port group, 1≤i≤R, i is a positive integer, R is the quantity of the DMRS port
groups, R is a positive integer greater than or equal to 2,

, Li is a quantity of transport layers corresponding to the ith DMRS port group, and ql is a modulation order corresponding to an lth transport layer; and
a kth data bit sequence is a data bit sequence obtained by sequentially extracting first
Qi data bits in the second preset order from a remaining data bit sequence included
in the CBG corresponding to each DMRS port group and performing serial concatenation
on the first Qi data bits, where 2≤k≤m, and the remaining data bit sequence included
in the CBG corresponding to the DMRS port group includes a data bit that remains after
data bit extraction is performed k-1 times on the data bit sequence included in the
CBG corresponding to the DMRS port group.
[0016] According to a second aspect, an embodiment of the invention provides a data communication
method, including:
obtaining, by a terminal device, configuration information of demodulation reference
signal DMRS port groups, where a quantity of the DMRS port groups is greater than
or equal to 2; and
communicating, by the terminal device, data with a network device, where the data
is corresponding to a transport block, the transport block is divided into at least
one code block group CBG, and each of the at least one CBG is corresponding to one
DMRS port group and is mapped to a transport layer corresponding to the one DMRS port
group.
[0017] According to the data transmission method provided in the second aspect, the terminal
device communicates the data with the network device, where the data is corresponding
to the transport block, the transport block is divided into the at least one code
block group CBG, and each of the at least one CBG is corresponding to one DMRS port
group and is mapped to a transport layer corresponding to the one DMRS port group.
It can be learned that, it is ensured that data flows sent through different DMRS
port groups belong to different CBGs, so that the network device can independently
decode a CBG corresponding to each DMRS port group, in other words, can independently
decode data flows mapped to different transport layers.
[0018] In a possible design, that the transport block is divided into at least one CBG includes:
the transport block with an added redundancy check bit is divided into N code blocks
CBs, where N = ┌B / c┐, B represents a total quantity of bits of the transport block with the added redundancy
check bit, C represents a preset value, and ┌ ┐ represents a round-up operation; and
the N CBs are grouped into CBGs corresponding to the DMRS port groups. In a possible
design, a quantity of CBs included in each CBG is equal to a value calculated based
on the following formula: └(B0 / Bs)× N┘or ┌(B0 / Bs)× N, where
B0 represents a quantity of bits of data sent through a DMRS port group corresponding
to the CBG, Bs represents a total quantity of bits of data sent through the DMRS port groups, |_
J represents a round-down operation, and ┌ ┐ represents a round-up operation.
[0019] In a possible design, that the transport block is divided into at least one CBG includes:
the transport block is divided into a transport sub-block corresponding to each DMRS
port group; and
each transport sub-block is encoded to obtain a CBG corresponding to the DMRS port
group.
[0020] In a possible design, the obtaining, by a terminal device, configuration information
of demodulation reference signal DMRS port groups includes:
receiving, by the terminal device, a notification message sent by the network device,
where the notification message carries the configuration information of the DMRS port
groups. In a possible design, that each of the at least one CBG is mapped to a transport
layer corresponding to the one DMRS port group includes:
a preset quantity of data bits are sequentially extracted in a first preset order
from a data bit sequence included in a CBG corresponding to each DMRS port group,
and serial concatenation is performed on the data bits to obtain a concatenated data
bit sequence; and
the concatenated data bit sequence is mapped to each transport layer according to
a predefined mapping policy.
[0021] According to the invention, the fact that a preset quantity of data bits are sequentially
extracted in a first preset order from a data bit sequence included in a CBG corresponding
to each DMRS port group, and serial concatenation is performed on the data bits to
obtain a concatenated data bit sequence includes:
when extraction is performed m times on the data bit sequence included in the CBG
corresponding to each DMRS port group to extract the entire data bit sequence, serial
concatenation is sequentially performed on a first data bit sequence to an mth data bit sequence to obtain the concatenated data bit sequence, where m is a total
quantity of times of performing extraction on the data bit sequence included in the
CBG corresponding to each DMRS port group, and m is a positive integer greater than
or equal to 2, where
the first data bit sequence is a data bit sequence obtained by sequentially extracting
first Qi data bits in a second preset order from the data bit sequence included in
the CBG corresponding to each DMRS port group and performing serial concatenation
on the first Qi data bits, where Qi represents a quantity of data bits extracted from
a data bit sequence included in a CBG corresponding to an ith DMRS port group, 1≤i≤R, i is a positive integer, R is the quantity of the DMRS port
groups, R is a positive integer greater than or equal to 2,

, Li is a quantity of transport layers corresponding to the ith DMRS port group, and ql is a modulation order corresponding to an lth transport layer; and
a kth data bit sequence is a data bit sequence obtained by sequentially extracting first
Qi data bits in the second preset order from a remaining data bit sequence included
in the CBG corresponding to each DMRS port group and performing serial concatenation
on the first Qi data bits, where 2≤k≤m, and the remaining data bit sequence included
in the CBG corresponding to the DMRS port group includes a data bit that remains after
data bit extraction is performed k-1 times on the data bit sequence included in the
CBG corresponding to the DMRS port group.
[0022] According to third and fourth aspects of the invention, a network device and a terminal
device are provided to perform the respective method steps as described above.
DESCRIPTION OF DRAWINGS
[0023]
FIG. 1 is a framework diagram of a communications system;
FIG. 2A is a schematic flowchart of Embodiment 1 of a data communication method according
to this application;
FIG. 2B is a schematic diagram of CB division according to an embodiment of this application;
FIG. 3 is a schematic flowchart of Embodiment 2 of a data communication method according
to this application;
FIG. 4 is a schematic flowchart of Embodiment 3 of a data communication method according
to this application;
FIG. 5 is a schematic flowchart of Embodiment 4 of a data communication method according
to this application;
FIG. 6 is a schematic flowchart of Embodiment 5 of a data communication method according
to this application;
FIG. 7 is a schematic flowchart of Embodiment 6 of a data communication method according
to this application;
FIG. 8 is a schematic structural diagram of Embodiment 1 of a network device according
to this application;
FIG. 9 is a schematic structural diagram of Embodiment 2 of a network device according
to this application;
FIG. 10 is a schematic structural diagram of Embodiment 1 of a terminal device according
to this application; and
FIG. 11 is a schematic structural diagram of Embodiment 2 of a terminal device according
to this application.
DESCRIPTION OF EMBODIMENTS
[0024] First, a communications system and some terms included in the embodiments of this
application are described.
[0025] FIG. 1 is a framework diagram of a communications system. As shown in FIG. 1, the
communications system includes a network device 01 and a terminal device 02. Optionally,
the communications system may be a long term evolution (Long Term Evolution, LTE)
communications system, or a 5
th generation (5-Generation, 5G) mobile communications system, for example, a new generation
(New Radio, NR) radio access technology. This is not limited herein.
[0026] The network device included in this application may include but is not limited to
a base station and a transmission reception point (Transmission Reception Point, TRP).
The base station is also referred to as a radio access network (Radio Access Network,
RAN) device, and is a device that connects a terminal to a wireless network. The base
station may be a base transceiver station (Base Transceiver Station, BTS) in global
system for mobile communications (Global System of Mobile communication, GSM) or code
division multiple access (Code Division Multiple Access, CDMA); or may be a NodeB
(NodeB, NB) in wideband code division multiple access (Wideband Code Division Multiple
Access, WCDMA); or may be an evolved NodeB (Evolutional Node B, eNB or eNodeB) in
long term evolution (Long Term Evolution, LTE), a relay station, an access point,
a base station on a future 5G network, or the like. This is not limited herein.
[0027] The terminal device may be a wireless terminal or a wired terminal. The wireless
terminal may be a device that provides voice and/or other service data connectivity
for a user, a handheld device with a wireless connection function, or another processing
device connected to a wireless modem. The wireless terminal may communicate with one
or more core networks through a radio access network (Radio Access Network, RAN).
The wireless terminal may be a mobile terminal, for example, a mobile phone (also
referred to as a "cellular" phone) or a computer with a mobile terminal. For example,
the wireless terminal may be a portable, pocket-sized, handheld, computer built-in,
or in-vehicle mobile apparatus, which exchanges voice and/or data with the radio access
network. For example, the wireless terminal may be a device such as a personal communication
service (Personal Communication Service, PCS) phone, a cordless phone, a session initiation
protocol (Session Initiation Protocol, SIP) phone, a wireless local loop (Wireless
Local Loop, WLL) station, or a personal digital assistant (Personal Digital Assistant,
PDA). The wireless terminal may also be referred to as a system, a subscriber unit
(Subscriber Unit), a subscriber station (Subscriber Station), a mobile station (Mobile
Station), a mobile (Mobile), a remote station (Remote Station), a remote terminal
(Remote Terminal), an access terminal (Access Terminal), a user terminal (User Terminal),
a user agent (User Agent), a user device (User Device or User Equipment). This is
not limited herein.
[0028] In the embodiments of this application, a DMRS port is an antenna port used to send
a DMRS. The antenna port is also used to send a physical data channel or a physical
control channel. The DMRS sent through the antenna port may be used to perform channel
estimation and signal demodulation on the physical data channel or the physical control
channel sent through the antenna port. A DMRS port, a DMRS antenna port, and the like
are not differentiated in the embodiments of this application, and are corresponding
to a same meaning.
[0029] In the embodiments of this application, DMRS ports in a DMRS port group meet a quasi-co-location
(Quasi-Co-Location, QCL) requirement, and two DMRS ports belonging to different DMRS
port groups do not meet the QCL requirement. Usually, if a large scale feature corresponding
to a channel that a signal sent through an antenna port goes through can be obtained
based on a large scale feature corresponding to a channel that a signal sent through
another antenna port goes through, it is considered that these two antenna ports meet
the QCL requirement. The large scale feature includes but is not limited to delay
spread, an average delay, average power, Doppler spread, a Doppler shift, and spatial
information (for example, an angle of arrival and a receive antenna correlation).
[0030] In the embodiments of this application, the network device may be configured to perform
coherent MIMO communication (that is, DMRS ports corresponding to different antenna
panels in the network device belong to a same DMRS port group, or DMRS ports corresponding
to the network device and another network device belong to a same DMRS port group),
or may be configured to perform non-coherent MIMO communication (that is, DMRS ports
corresponding to different antenna panels in the network device belong to different
DMRS port groups, or DMRS ports corresponding to the network device and another network
device belong to different DMRS port groups). The following embodiment part separately
describes the two scenarios.
[0031] In the embodiments of this application, a process of mapping a CBG or a transport
block to a corresponding transport layer further includes but is not limited to the
following process: sequentially performing processes such as scrambling, modulation,
and layer mapping on the CBG or the transport block. Specifically, for implementation
processes of scrambling, modulation, and layer mapping, refer to the following processes
in the version 12.5.0 (v12.5.0) of the 3
rd generation partnership project (3
rd Generation Partnership Project, 3GPP) long term evolution (Long Term Evolution, LTE)
system technical specification (Technical Specification, TS) 36.211: a physical uplink
shared channel scrambling process in the section 5.3.1, physical uplink shared channel
modulation and layer mapping processes in the section 5.3.2, a physical downlink shared
channel scrambling process in the section 6.3.1, a physical downlink shared channel
modulation process in the section 6.3.2, and a layer mapping process during spatial
multiplexing transmission of a physical downlink shared channel in the section 6.3.3.2.
Details are not described herein. It can be understood that the process of mapping
a CBG or transport block to a corresponding transport layer may be alternatively performed
in another existing manner or a future manner. This is not limited in the embodiments
of this application.
[0032] In the embodiments of this application, a mapping relationship between a DMRS port
group and a corresponding transport layer is predefined in the network device and/or
the terminal device, or the network device dynamically configures, by using a higher
layer message or a physical layer message, a mapping relationship, between a DMRS
port group and a corresponding transport layer, in the network device and/or the terminal
device, so that a transport layer to which data corresponding to a DMRS port group
is mapped can be learned of when the DMRS port group is learned of. In the embodiments
of this application, one antenna port is used to send a data flow corresponding to
one transport layer. Therefore, it can be considered that a transport layer and an
antenna port are in a one-to-one mapping relationship. In the embodiments of this
application, a transport layer and an antenna port may not be differentiated, and
may be considered as equivalent based on a mapping relationship.
[0033] By using specific embodiments, the following describes in detail a data communication
method, a network device, and a terminal device provided in the embodiments of this
application.
[0034] FIG. 2A is a schematic flowchart of Embodiment 1 of a data communication method according
to this application. This embodiment of this application describes non-coherent MIMO
communication (that is, there are a plurality of DMRS antenna port groups). As shown
in FIG. 2A, the method in this embodiment may include the following steps.
[0035] Step S201: A network device determines DMRS port groups.
[0036] In this step, the network device determines the DMRS port groups used by the network
device to communicate data with a terminal device. Optionally, a quantity of the DMRS
port groups is greater than or equal to 2. Optionally, the network device performs
user scheduling and resource allocation with reference to network load and an interference
status and based on channel state information fed back by the terminal device, an
uplink sounding reference signal sent by the terminal device, or the like, to determine
the DMRS port groups used by the network device to communicate data with the terminal
device. Certainly, the network device may alternatively determine the DMRS port groups
in another manner. This is not limited in this embodiment of this application.
[0037] Step S202: A terminal device obtains configuration information of the demodulation
reference signal DMRS port groups.
[0038] In this step, manners of obtaining, by the terminal device, the configuration information
of the DMRS port groups may include but are not limited to the following manners:
receiving, by the terminal device, a notification message (optionally, the notification
message carries the configuration information of the DMRS port groups, and information
about antenna ports included in the DMRS port groups) sent by the network device;
or obtaining, by the terminal device, predefined configuration information of the
DMRS port groups. Optionally, the notification message may include but is not limited
to any one of or a combination of the following: downlink control information (Downlink
Control Information, DCI), a radio resource control (Radio Resource Control, RRC)
message, and a media access control control element (Media Access Control Control
Element, MAC CE).
[0039] Step S203: The network device and the terminal device perform data communication.
[0040] The data is corresponding to a transport block. The transport block is divided into
at least one code block group CBG. Each of the at least one CBG is corresponding to
one DMRS port group (that is, different DMRS port groups are corresponding to different
CBGs, and one CBG is not corresponding to a plurality of DMRS port groups) and is
mapped to a transport layer corresponding to the one DMRS port group.
[0041] In this step, (1) for downlink data transmission, the network device sends data to
the terminal device, where the data is corresponding to a transport block, (Transport
Block, TB). The network device divides the transport block into at least one code
block group CBG. Each of the at least one CBG is corresponding to one DMRS port group
(that is, different DMRS port groups are corresponding to different CBGs, and one
CBG is not corresponding to a plurality of DMRS port groups), and each of the at least
one CBG is mapped to a transport layer corresponding to the one DMRS port group. For
example, the network device determines that the DMRS port groups include a DMRS port
group 1 and a DMRS port group 2 (that is, the quantity of the DMRS port groups is
equal to 2). In this case, the transport block is divided into two CBGs (including
a CBG 1 corresponding to the DMRS port group 1 and a CBG 2 corresponding to the DMRS
port group 2), and the CBG 1 is mapped to a transport layer corresponding to the DMRS
port group 1, and the CBG 2 is mapped to a transport layer corresponding to the DMRS
port group 2. Optionally, the transport block may be alternatively divided into CBGs
whose quantity is an integer multiple of the quantity of the DMRS port groups (for
example, the transport block is divided into a CBG 1 to a CBG 4). Correspondingly,
each DMRS port group is corresponding two CBGs (for example, the DMRS port group 1
is corresponding to the CBG 1 and the CBG 2, and the DMRS port group 2 is corresponding
to the CBG 3 and the CBG 4). It can be learned that, it is ensured that data flows
sent through different DMRS port groups belong to different CBGs, so that the terminal
device can independently decode a CBG corresponding to each DMRS port group.
[0042] Correspondingly, the terminal device receives the data sent by the network device,
and decodes the received data based on the learned DMRS port groups (for example,
learns of the DMRS port groups based on the configuration information of the DMRS
port groups in step S202). For example, the terminal device can learn of a division
manner of the transport block (for example, a quantity of CBGs into which the transport
block is divided) and a resource mapping manner of the transport block (for example,
a transport layer to which the transport block is mapped) based on the DMRS port groups,
so that the terminal device can independently decode a CBG corresponding to each DMRS
port group.
[0043] (2) For uplink data transmission, after the terminal device learns of the configuration
information of the DMRS port groups (in other words, learns of the DMRS port groups),
the terminal device sends data to the network device, where the data is corresponding
to a transport block (for example, a TB). The terminal device divides the transport
block into at least one code block group CBG. Each of the at least one CBG is corresponding
to one DMRS port group (that is, different DMRS port groups are corresponding to different
CBGs, and one CBG is not corresponding to a plurality of DMRS port groups), and each
of the at least one CBG is mapped to a transport layer corresponding to the one DMRS
port group. It can be learned that, it is ensured that data flows sent through different
DMRS port groups belong to different CBGs, so that the network device can independently
decode a CBG corresponding to each DMRS port group.
[0044] Correspondingly, the network device receives the data sent by the terminal device,
and decodes the received data based on the determined DMRS antenna port groups. For
example, the network device can learn of a division manner of the transport block
(for example, a quantity of CBGs into which the transport block is divided) and a
resource mapping manner of the transport block (for example, a transport layer to
which the transport block is mapped) based on the DMRS port groups, so that the network
device can independently decode a CBG corresponding to each DMRS port group.
[0045] Optionally, for the foregoing downlink data transmission and/or uplink data transmission,
implementations of dividing the transport block into the at least one CBG may include
but are not limited to the following two implementations.
[0046] In a first implementation, the transport block with an added redundancy check bit
is divided into N code blocks CBs, where
N = ┌
B /
c┐
, B represents a total quantity of bits of the transport block with the added redundancy
check bit, C represents a preset value (that is, a maximum quantity of bits included
in a CB, for example, 6144 or 8196), and ┌ ┐ represents a round-up operation. The
N CBs are grouped into CBGs corresponding to the DMRS port groups (that is, each DMRS
port group is corresponding to at least one CBG, different DMRS port groups are corresponding
to different CBGs, and one CBG is not corresponding to a plurality of DMRS port groups).
Optionally, a specific manner of concatenating the N CBs in the process of grouping
the N CBs into the CBGs corresponding to the DMRS port groups is not limited in this
embodiment of this application. Optionally, a quantity of CBs included in each CBG
is equal to a value calculated based on the following formula: └(
B0 /
Bs)×
N┘ or ┌(
B0 /
Bs)×
N┐. Optionally, a total quantity of CBs included in all CBGs is equal to a total quantity
N of CBs in a system.
B0 represents a quantity of bits of data sent through a DMRS port group corresponding
to the CBG,
Bs represents a total quantity of bits of data sent through the DMRS port groups, └
┘ represents a round-down operation, and ┌ ┐ represents a round-up operation. Optionally,
a quantity of bits of data sent through each DMRS port is equal to a modulation and
coding scheme (Modulation and Coding Scheme, MCS) at a transport layer corresponding
to the DMRS port × a quantity of transport layers corresponding to the DMRS port ×
a quantity of physical time-frequency resource elements (Resource Element, RE) that
are used for data communication and that are allocated to the transport layer corresponding
to the DMRS port.
[0047] For example, assuming that a quantity of bits of data sent through the DMRS port
group 1 is B1, a quantity of bits of data sent through the DMRS port group 2 is B2,
and the transport block is divided into N code blocks CBs, a quantity of CBs included
in the CBG 1 corresponding to the DMRS port group 1 is equal to

, and correspondingly, a quantity of CBs included in the CBG 2 corresponding to the
DMRS port group 2 is equal to a value of N-

. Alternatively, a quantity of CBs included in the CBG 1 corresponding to the DMRS
port group 1 is equal to

, and correspondingly, a quantity of CBs included in the CBG 2 corresponding to the
DMRS port group 2 is equal to a value of N-

.
[0048] Optionally, for a process of dividing the transport block into the N code blocks
CBs, refer to processes of segmenting code blocks and redundancy check in the section
5.1.2 in the version 13.1.0 (vl3.1.0) of 3GPP LTE TS 36.212. Details are not described
herein. It can be understood that the process of dividing the transport block into
the CBs may be alternatively performed in another existing manner or a future manner,
and a parameter used in the division process may be different from that in the existing
solution. This is not limited in this embodiment of the present invention. For example,
FIG. 2B is a schematic diagram of CB division according to an embodiment of this application.
As shown in FIG. 2B, a transport block (for example, a TB) may be considered as media
access control (Media Access Control, MAC) layer data, and the transport block with
added cyclic redundancy check (Cyclic Redundancy Check, CRC) is usually divided into
N CBs. Then independent CRC is applied to each CB, and each CB is encoded to obtain
N encoded CBs.
[0049] In a second implementation, the transport block is divided into a transport sub-block
corresponding to each DMRS port group (that is, each DMRS port group is corresponding
to one transport sub-block, different DMRS port groups are corresponding to different
transport sub-blocks, and one transport sub-block is not corresponding to a plurality
of DMRS port groups); and each transport sub-block is encoded to obtain a CBG corresponding
to the DMRS port group. Optionally, for a process of coding each transport sub-block,
refer to a general coding process in the section 5.1 in the version 13.1.0 (vl3.1.0)
of 3GPP LTE TS 36.212. Details are not described herein. It can be understood that
the process of coding the transport sub-block may be alternatively performed in another
existing manner or a future manner, and a parameter used in the coding process may
be different from that in the existing solution. This is not limited in this embodiment
of the present invention.
[0050] In this embodiment of this application, sequence numbers of the foregoing steps constitute
no limitation on execution sequences, and the execution sequences of the steps should
be determined based on functions and internal logic of the steps. This is not limited
in this embodiment of this application.
[0051] In this embodiment of this application, the network device and the terminal device
perform data communication, where the data is corresponding to the transport block,
the transport block is divided into the at least one code block group CBG, and each
of the at least one CBG is corresponding to one DMRS port group and is mapped to a
transport layer corresponding to the one DMRS port group. It can be learned that,
it is ensured that data flows sent through different DMRS port groups belong to different
CBGs, so that a receive end can independently decode a CBG corresponding to each DMRS
port group (in other words, can independently decode data flows mapped to different
transport layers), and therefore can support interference cancellation performed by
an interference cancellation receiver.
[0052] Further, because the receive end can independently decode the CBG corresponding to
each DMRS port group, the receive end can perform ACK/NACK feedback in a form of a
CBG. For example, when correctly decoding a CBG, the receive end feeds back an ACK;
otherwise, the receive end feeds back a NACK. Correspondingly, a transmit end needs
to retransmit the CBG incorrectly decoded by the receive end, until the receive end
correctly receives the CBG or a maximum quantity of retransmission times is reached.
Optionally, by default, a mapped-to transport layer during retransmission may be the
same as a mapped-to transport layer during initial transmission; or certainly, an
exchange identifier may be used to indicate that a mapped-to transport layer during
retransmission is different from a mapped-to transport layer during initial transmission.
For example, assuming that the CBG 1 and the CBG 2 are incorrectly decoded, and that
during initial transmission, the CBG 1 is mapped to first two layers and the CBG 2
is mapped to last two layers, based on an exchange identifier, during retransmission,
the CBG 1 is mapped to the last two layers and the CBG 2 is mapped to the first two
layers. For another example, assuming that the CBG 1 is incorrectly decoded, by default,
a transport layer to which the CBG 1 is mapped during retransmission is the same as
a transport layer to which the CBG is mapped during initial transmission; or an exchange
identifier may be used to indicate that a transport layer to which the CBG 1 is mapped
during retransmission is the same as a transport layer to which the CBG 2 is mapped
during initial transmission.
[0053] The foregoing embodiment of this application mainly describes the following: Transport
block division is performed at different transport layers or different antenna ports
during MIMO communication based on a quantity of DMRS port groups, so that each DMRS
port group is corresponding to at least one CBG. Optionally, if division in time domain
and/or frequency domain are/is further used, the at least one CBG corresponding to
each DMRS port group may be corresponding to different symbol groups in time domain,
and/or may be corresponding to different subband groups in frequency domain. For example,
assuming that a DMRS port group is corresponding to a CBG 1 to a CBG 3, if division
in time domain is further used, the CBG 1 and the CBG 2 are corresponding to a symbol
group 1, and the CBG 3 is corresponding to a symbol group 2; or if division in frequency
domain is further used, the CBG 1 is corresponding to a subband group 1, and the CBG
2 and the CBG 3 are corresponding to a subband group 2.
[0054] Correspondingly, in addition to space domain (that is, a transport layer or an antenna
port), a CBG may be further mapped in time domain and/or frequency domain. For example,
layer mapping (the resource mapping manner described in Embodiment 1 of this application),
frequency-domain mapping, and time-domain mapping are sequentially performed. For
specific frequency-domain mapping and/or time-domain mapping, refer to existing mapping
manners. For example, time-domain mapping is performed based on a symbol group (including
at least one symbol), and/or frequency-domain mapping is performed based on a subband
group (including at least one subband).
[0055] FIG. 3 is a schematic flowchart of Embodiment 2 of a data communication method according
to this application. Based on the foregoing embodiment, this embodiment of this application
describes downlink non-coherent MIMO communication (that is, there are a plurality
of DMRS antenna port groups). As shown in FIG. 3, the method in this embodiment may
include the following steps.
[0056] Step S301: A network device determines demodulation reference signal DMRS port groups.
In this step, the network device determines the DMRS port groups used by the network
device to send data to a terminal device. Optionally, a quantity of the DMRS port
groups is greater than or equal to 2.
[0057] Step S302: The network device sends a notification message and data to a terminal
device.
[0058] Optionally, the notification message carries configuration information of the DMRS
port groups, so that the terminal device can learn of the DMRS port groups based on
the notification message. Optionally, the data is corresponding to a transport block.
The network device divides the transport block into at least one code block group
CBG. Each of the at least one CBG is corresponding to one DMRS port group, and each
of the at least one CBG is mapped to a transport layer corresponding to the one DMRS
port group. For a specific division manner, refer to Embodiment 1 of this application.
For a resource mapping manner, refer to Embodiment 1 or Embodiment 7 of this application.
Details are not described herein again.
[0059] Step S303: The terminal device receives the notification message and the data.
[0060] In this step, the terminal device determines the DMRS port groups based on the notification
message, and can learn of the division manner of the transport block (for example,
a quantity of CBGs into which the transport block is divided) and the resource mapping
manner of the transport block (for example, a transport layer to which the transport
block is mapped) based on the DMRS port groups, so that the terminal device can independently
decode a CBG corresponding to each DMRS port group (in other words, can independently
decode data flows mapped to different transport layers), and can support interference
cancellation performed by an interference cancellation receiver.
[0061] FIG. 4 is a schematic flowchart of Embodiment 3 of a data communication method according
to this application. Based on the foregoing embodiment, this embodiment of this application
describes uplink non-coherent MIMO communication (that is, there are a plurality of
DMRS antenna port groups). As shown in FIG. 4, the method in this embodiment may include
the following steps.
[0062] Step S401: A terminal device obtains configuration information of demodulation reference
signal DMRS port groups.
[0063] In this step, the terminal device learns, based on the configuration information
of the DMRS port groups, of the DMRS port groups used by the terminal device to send
data to a network device. Optionally, a quantity of the DMRS port groups is greater
than or equal to 2. Optionally, the configuration information of the DMRS port groups
may be notified by the network device to the terminal device, or may be predefined
in the terminal device (correspondingly, configuration information of the DMRS port
groups is also predefined in the network device). Step S402: The terminal device sends
data to a network device.
[0064] Optionally, the data is corresponding to a transport block. The terminal device divides
the transport block into at least one code block group CBG. Each of the at least one
CBG is corresponding to one DMRS port group, and each of the at least one CBG is mapped
to a transport layer corresponding to the one DMRS port group. For a specific division
manner, refer to Embodiment 1 of this application. For a resource mapping manner,
refer to Embodiment 1 or Embodiment 7 of this application. Details are not described
herein again.
[0065] Step S403: The network device receives the data.
[0066] In this step, the network device can learn of the division manner of the transport
block (for example, a quantity of CBGs into which the transport block is divided)
and the resource mapping manner of the transport block (for example, a transport layer
to which the transport block is mapped) based on the DMRS port groups used by the
terminal device to send the data to the network device, so that the network device
can independently decode a CBG corresponding to each DMRS port group.
[0067] FIG. 5 is a schematic flowchart of Embodiment 4 of a data communication method according
to this application. This embodiment of this application describes coherent MIMO communication
(that is, there is one DMRS antenna port group). As shown in FIG. 5, the method in
this embodiment may include the following steps.
[0068] Step S501: A network device determines a quantity of transport layers.
[0069] In this step, the network device determines a quantity of transport layers corresponding
to each transport block (for example, TB). Optionally, the network device determines,
based on scheduling result information (for example, a downlink reference signal for
measurement or an uplink sounding reference signal) sent by a terminal device, a total
quantity of transport layers used for data communication between the network device
and the terminal device. Usually, when the total quantity of transport layers is greater
than or equal to 1 and less than or equal to 4, transmission for one transport block
is supported; or when the total quantity of transport layers is greater than 4 and
less than or equal to 8, transmission for two transport blocks is supported. It can
be learned that when the total quantity of transport layers is determined, the network
device can learn of the quantity of transport layers corresponding to each transport
block. Certainly, the network device may alternatively determine the quantity of transport
layers in another manner. This is not limited in this embodiment of this application.
[0070] Step S502: A terminal device obtains the quantity of transport layers.
[0071] In this step, manners of obtaining the quantity of transport layers by the terminal
device may include but are not limited to the following manners: receiving, by the
terminal device, a notification message (optionally, the notification message carries
configuration information of the quantity of transport layers) sent by the network
device; or obtaining, by the terminal device, predefined configuration information
of the quantity of transport layers. Optionally, the notification message may include
but is not limited to any one of the following: downlink control information (Downlink
Control Information, DCI), a radio resource control (Radio Resource Control, RRC)
message, and a MAC CE.
[0072] Optionally, the notification message may further carry information about an antenna
port included in the DMRS port group, so that the terminal device can learn of an
antenna port used for data communication. Optionally, the terminal device may alternatively
obtain predefined information about an antenna port included in the DMRS port group.
Certainly, the terminal device may alternatively obtain the information about the
antenna port in another manner. This is not limited in this embodiment of this application.
[0073] Step S503: The network device and the terminal device perform data communication.
[0074] In this step, (1) for downlink data transmission, the network device sends data to
the terminal device, where the data is corresponding to a transport block (for example,
a TB), and the transport block is mapped to a corresponding transport layer based
on the quantity of transport layers.
[0075] Optionally, implementations of mapping the transport block to the corresponding transport
layer based on the quantity of transport layers include but are not limited to the
following two implementations.
[0076] In a first implementation, if the quantity of transport layers is greater than or
equal to 1 and less than or equal to 4, the transport block is mapped to the corresponding
transport layer. For example, when the quantity of transport layers is equal to 1,
the transport block is mapped to corresponding one transport layer; when the quantity
of transport layers is equal to 2, the transport block is mapped to corresponding
two transport layers; when the quantity of transport layers is equal to 3, the transport
block is sequentially mapped to corresponding three transport layers; or when the
quantity of transport layers is equal to 4, the transport block is sequentially mapped
to corresponding four transport layers. Optionally, the network device indicates,
by using dynamic signaling or a predefined rule, a relationship between a transport
layer and an antenna port used to send a data flow at the transport layer, so that
after learning of an antenna port used for sending, the terminal device maps the transport
block to a transport layer corresponding to the antenna port, and sends a data flow
at the transport layer through the antenna port.
[0077] In a second implementation: (A) if the quantity of transport layers is equal to 1
or 2, the transport block is mapped to the corresponding transport layer. For example,
when the quantity of transport layers is equal to 1, the transport block is mapped
to corresponding one transport layer; or when the quantity of transport layers is
equal to 2, the transport block is mapped to corresponding two transport layers. (B)
If the quantity of transport layers is equal to 3 or 4, the transport block is divided
into two code block groups CBGs, and the two CBGs are mapped to different transport
layers; or the transport block is mapped to corresponding transport layers (for example,
three transport layers or four transport layers). Optionally, the transport block
is mapped to corresponding transport layers according to a predefined rule or a rule
that is indicated by a dynamic configuration message. For example, when the quantity
of transport layers is equal to 3, the transport block is divided into a CBG 1 and
a CBG 2, the CBG 1 is mapped to any one of the three layers, and the CBG 2 is mapped
to the other two transport layers, of the three layers, different from the transport
layer to which the CBG 1 is mapped; or the CBG 1 is mapped to any two of the three
layers, and the CBG 2 is mapped to the other transport layer, of the three layers,
different from the transport layers to which the CBG 1 is mapped. For another example,
when the quantity of transport layers is equal to 4, the transport block is divided
into a CBG 1 and a CBG 2, the CBG 1 is mapped to any two transport layers (for example,
first two layers) of the four layers, and the CBG 2 is mapped to the other two transport
layers (for example, last two transport layers), of the four layers, different from
the transport layers to which the CBG 1 is mapped.
[0078] Optionally, according to the second implementation, the method further includes:
determining, by the network device based on that a difference between channel quantity
information corresponding to different DMRS ports is greater than a preset threshold,
to divide the transport block when the quantity of transport layers is equal to 3
or 4. In other words, when the difference between channel quantity information corresponding
to different DMRS ports is less than or equal to the preset threshold, the network
device determines not to divide the transport block when the quantity of transport
layers is equal to 3 or 4. Optionally, the network device may alternatively determine,
according to a service requirement, whether to divide the transport block when the
quantity of transport layers is equal to 3 or 4. Optionally, for a delay-sensitive
service, the network device may determine that the transport block does not need to
be divided when the quantity of transport layers is equal to 3 or 4. For a non-delay-sensitive
service, the network device may determine to divide the transport block when the quantity
of transport layers is equal to 3 or 4. The delay-sensitive service is a service that
requires that ACK/NACK feedback be performed within one subframe, for example, an
ultra low latency and reliability connection (Ultra Low Latency and Reliability Connection,
ULLRC) service; on the contrary, a service that does not require that ACK/NACK feedback
be performed within one subframe is a non-delay-sensitive service, for example, a
mobile broadband (Mobile BroadBand, MBB) service.
[0079] To ensure that the terminal device side can learn of division and mapping manners
used on the network device side, the method further includes: sending, by the network
device, a group configuration message to the terminal device, where the group configuration
message is used to instruct to divide the transport block when the quantity of transport
layers is equal to 3 or 4. Optionally, the group configuration message may be carried
in any one of the following information: DCI, an RRC message, and a MAC CE. Certainly,
the group configuration message may be alternatively carried in other information.
This is not limited in this embodiment of this application.
[0080] Correspondingly, the terminal device receives the data sent by the network device.
When the terminal device does not receive the group configuration message, the terminal
device directly decodes the received data based on the learned quantity of transport
layers (for example, based on the quantity of transport layers that is obtained in
step S502). For example, the terminal device can learn of a resource mapping manner
of the data (for example, a transport layer to which the data is mapped) based on
the quantity of transport layers. When receiving the group configuration message,
the terminal device can learn, based on the quantity of transport layers, of a resource
mapping manner used when the quantity of transport layers is equal to 1 or 2, and
can determine, based on the group configuration message, resource division (for example,
a quantity of CBGs into which the data is divided) and mapping (for example, a transport
layer to which the data is mapped) manners used when the quantity of transport layers
is equal to 3 or 4.
[0081] (2) For uplink data transmission, the terminal device sends data to the network device,
where the data is corresponding to a transport block (for example, a TB), and the
transport block is mapped to a corresponding transport layer based on the quantity
of transport layers. Optionally, implementations of mapping the transport block to
the corresponding transport layer based on the quantity of transport layers include
but are not limited to the following two implementations.
[0082] In a first implementation, if the quantity of transport layers is greater than or
equal to 1 and less than or equal to 4, the transport block is mapped to the corresponding
transport layer. For example, when the quantity of transport layers is equal to 1,
the transport block is mapped to corresponding one transport layer; when the quantity
of transport layers is equal to 2, the transport block is mapped to corresponding
two transport layers; when the quantity of transport layers is equal to 3, the transport
block is sequentially mapped to corresponding three transport layers; or when the
quantity of transport layers is equal to 4, the transport block is sequentially mapped
to corresponding four transport layers.
[0083] In a second implementation: (A) if the quantity of transport layers is equal to 1
or 2, the transport block is mapped to the corresponding transport layer. (B) If the
quantity of transport layers is equal to 3 or 4, and a group configuration message
is used to instruct to divide the transport block, the transport block is divided
into two code block groups CBGs, and the two CBGs are mapped to different transport
layers; or if the group configuration message is not obtained, the transport block
is mapped to corresponding transport layers. For example, if the terminal device obtains
the group configuration message, the transport block is divided into two CBGs; or
if the terminal device does not obtain the group configuration message, the transport
block is directly mapped to corresponding transport layers. Optionally, the terminal
device may obtain the group configuration message by receiving the group configuration
message sent by the network device, or may obtain the group configuration message
by obtaining a preconfigured group configuration message, or certainly, may obtain
the group configuration message in another manner. This is not limited in this embodiment
of this application.
[0084] Correspondingly, the network device receives the data sent by the terminal device.
When the group configuration message is not obtained, the network device directly
decodes the received data based on the quantity of transport layers (for example,
based on the quantity of transport layers that is determined in step S501). For example,
the network device can learn of a resource mapping manner of the data (for example,
a transport layer to which the data is mapped) based on the quantity of transport
layers. When the group configuration message is obtained, the network device can learn,
based on the quantity of transport layers, of a resource mapping manner used when
the quantity of transport layers is equal to 1 or 2, and can determine, based on the
group configuration message, resource division (for example, a quantity of CBGs into
which the data is divided) and mapping (for example, a transport layer to which the
data is mapped) manners used when the quantity of transport layers is equal to 3 or
4.
[0085] In this embodiment of this application, sequence numbers of the foregoing steps constitute
no limitation on execution sequences, and the execution sequences of the steps should
be determined based on functions and internal logic of the steps. This is not limited
in this embodiment of this application.
[0086] In this embodiment of this application, the network device and the terminal device
perform data communication, where the data is corresponding to the transport block,
and the transport block is mapped to the corresponding transport layer based on the
quantity of transport layers. It can be learned that flexible resource mapping can
be implemented based on different quantities of transport layers, to adapt to different
service requirements, different transmission scenarios, different channel statuses,
or the like.
[0087] The foregoing embodiment of this application describes a mapping manner during initial
transmission, and the following part describes a mapping manner during retransmission.
Optionally, when a quantity of transport layers corresponding to a single transport
block is equal to 1 or 2, by default, a mapped-to transport layer during retransmission
is the same as a mapped-to transport layer during initial transmission. When a quantity
of transport layers corresponding to a single transport block is equal to 3 or 4,
by default, a mapped-to transport layer during retransmission may be the same as a
mapped-to transport layer during initial transmission; or certainly, an exchange identifier
may be used to indicate that a mapped-to transport layer during retransmission is
different from a mapped-to transport layer during initial transmission. For example,
assuming that the CBG 1 and the CBG 2 are incorrectly decoded, and that during initial
transmission, the CBG 1 is mapped to first two layers and the CBG 2 is mapped to last
two layers, based on an exchange identifier, during retransmission, the CBG 1 is mapped
to the last two layers and the CBG 2 is mapped to the first two layers. For another
example, assuming that the CBG 1 is incorrectly decoded, by default, a transport layer
to which the CBG 1 is mapped during retransmission is the same as a transport layer
to which the CBG is mapped during initial transmission; or an exchange identifier
may be used to indicate that a transport layer to which the CBG 1 is mapped during
retransmission is the same as a transport layer to which the CBG 2 is mapped during
initial transmission.
[0088] Optionally, in this embodiment of this application, for a manner of dividing the
transport block into one or more CBGs, refer to related content about that "the transport
block is divided into at least one CBG" in Embodiment 1 of this application. Details
are not described herein again. Optionally, in this embodiment of this application,
the CBG is obtained through transport block division merely at different transport
layers during MIMO communication, namely, division in space domain. If division in
time domain and/or frequency domain are/is further used, this embodiment of this application
is also applicable to a CBG obtained through transport block division in space domain
in combination with symbol division in time domain and/or subband division in frequency
domain, and certainly, is also applicable to other cases. This is not limited in this
embodiment of this application. Specifically, how to divide a transport block in time
domain and/or frequency domain and how to perform resource mapping in time domain
and/or frequency domain are not limited in this embodiment of this application.
[0089] The foregoing embodiment of this application mainly describes mapping of a transport
block in space domain. The transport block may be further mapped in time domain and/or
frequency domain. For example, layer mapping (the resource mapping manner described
in Embodiment 4 of this application), frequency-domain mapping, and time-domain mapping
are sequentially performed. For specific frequency-domain mapping and/or time-domain
mapping, refer to existing mapping manners. For example, time-domain mapping is performed
based on a symbol group (including at least one symbol), and/or frequency-domain mapping
is performed based on a subband group (including at least one subband).
[0090] FIG. 6 is a schematic flowchart of Embodiment 5 of a data communication method according
to this application. Based on Embodiment 4, this embodiment of this application describes
downlink coherent MIMO communication (that is, there is one DMRS antenna port group).
As shown in FIG. 6, the method in this embodiment may include the following steps.
[0091] Step S601: A network device determines a quantity of transport layers.
[0092] In this step, the network device determines a quantity of transport layers corresponding
to each transport block (for example, TB).
[0093] Step S602: The network device sends a notification message and data to a terminal
device.
[0094] Optionally, the notification message carries configuration information of the quantity
of transport layers, so that the terminal device can learn of the quantity of transport
layers based on the notification message. Optionally, the notification message may
further carry information about an antenna port included in the DMRS port group, so
that the terminal device can learn of an antenna port used for data communication.
[0095] Optionally, the data is corresponding to a transport block, and the transport block
is mapped to a corresponding transport layer based on the quantity of transport layers.
For a specific resource mapping manner, refer to Embodiment 4 of this application.
Details are not described herein again.
[0096] Step S603: The terminal device receives the notification message and the data.
[0097] In this step, the terminal device determines, based on the notification message,
the quantity of transport layers and the antenna port included in the DMRS port group.
When the terminal device does not receive a group configuration message sent by the
network device, the terminal device can directly learn of the resource mapping manner
of the transport block (for example, a transport layer to which the transport block
is mapped) based on the quantity of transport layers. When receiving a group configuration
message sent by the network device, the terminal device can learn, based on the quantity
of transport layers, of a resource mapping manner used when the quantity of transport
layers is equal to 1 or 2, and can learn, based on the group configuration message,
of resource division and mapping manners used when the quantity of transport layers
is equal to 3 or 4. It can be learned that flexible resource mapping can be implemented
based on different quantities of transport layers, to adapt to different service requirements,
different transmission scenarios, different channel statuses, or the like.
[0098] FIG. 7 is a schematic flowchart of Embodiment 6 of a data communication method according
to this application. Based on Embodiment 4, this embodiment of this application describes
uplink coherent MIMO communication (that is, there is one DMRS antenna port group).
As shown in FIG. 7, the method in this embodiment may include the following steps.
[0099] Step S701: A terminal device obtains configuration information of a quantity of transport
layers. In this step, the terminal device learns, based on the configuration information
of the quantity of transport layers, of a quantity of transport layers corresponding
to each transport block (for example, a TB). Optionally, the configuration information
of the quantity of transport layers may be notified by a network device to the terminal
device, or may be predefined in the terminal device (correspondingly, configuration
information of the quantity of transport layers is also predefined in the network
device). Optionally, the terminal device may further obtain information about an antenna
port included in the DMRS port group, and therefore can learn of an antenna port used
to send data to the network device. For a manner of obtaining the information about
the antenna port, refer to related descriptions in Embodiment 5 of this application.
Details are not described herein again.
[0100] Step S702: The terminal device sends data to the network device.
[0101] Optionally, the data is corresponding to a transport block, and the transport block
is mapped to a corresponding transport layer based on the quantity of transport layers.
For a specific resource mapping manner, refer to Embodiment 4 of this application.
Details are not described herein again.
[0102] Step S703: The network device receives the data.
[0103] In this step, the network device receives the data sent by the terminal device. When
no group configuration message is obtained, the network device can directly learn
of the resource mapping manner of the data (for example, a transport layer to which
the data is mapped) based on the quantity of transport layers. When a group configuration
message is obtained, the network device can learn, based on the quantity of transport
layers, of a resource mapping manner used when the quantity of transport layers is
equal to 1 or 2, and can learn, based on the group configuration message, resource
division (for example, a quantity of CBGs into which the data is divided) and mapping
(a transport layer to which the data is mapped) manners used when the quantity of
transport layers is equal to 3 or 4. It can be learned that flexible resource mapping
can be implemented based on different quantities of transport layers, to adapt to
different service requirements, different transmission scenarios, different channel
statuses, or the like.
[0104] In Embodiment 7 of the data communication method in this application, implementations
of that "each of the at least one CBG is mapped to a transport layer corresponding
to the one DMRS port group" in Embodiment 1 to Embodiment 3 are described.
[0105] Optionally, that each of the at least one CBG is mapped to a transport layer corresponding
to the one DMRS port group includes:
a preset quantity of data bits are sequentially extracted in a first preset order
from a data bit sequence included in a CBG corresponding to each DMRS port group,
and serial concatenation is performed on the data bits to obtain a concatenated data
bit sequence; and
the concatenated data bit sequence is mapped to each transport layer according to
a predefined mapping policy.
[0106] Optionally, that a preset quantity of data bits are sequentially extracted in a first
preset order from a data bit sequence included in a CBG corresponding to each DMRS
port group, and serial concatenation is performed on the data bits to obtain a concatenated
data bit sequence may be implemented in at least one of the following several implementations.
[0107] In a first implementation, for example, assuming that there are a total of three
DMRS port groups (a DMRS port group 1 to a DMRS port group 3, where a quantity of
DMRS port groups is certainly not limited thereto), a preset quantity of data bits
are sequentially extracted in a preset order from a data bit sequence included in
a CBG corresponding to each DMRS port group. Optionally, quantities of data bits extracted
from data bit sequences included in CBGs corresponding to different DMRS port groups
may be the same or different, in other words, preset quantities corresponding to different
DMRS port groups may be the same or different. It is assumed that extraction of the
data bit sequence included in the CBG corresponding to each DMRS port group is completed
at a time, that is, the preset order in the first implementation is the first preset
order. Further, serial concatenation is sequentially performed on the extracted data
bits to obtain the concatenated data bit sequence. Optionally, the preset order may
be an ascending order of sequence numbers of DMRS port groups, or a descending order
of sequence numbers of DMRS port groups, or another preset order, or a network-configured
order. The network-configured order may be explicitly indicated by using higher layer
signaling or physical layer signaling.
[0108] In a second implementation, for example, it is assumed that there are a total of
three DMRS port groups (a DMRS port group 1 to a DMRS port group 3, where a quantity
of DMRS port groups is certainly not limited thereto). (1) First, front data bits
of a preset quantity are sequentially extracted in a preset order (referred to as
a second preset order in the following embodiments, for example, an ascending order
of sequence numbers of DMRS port groups, or a descending order of sequence numbers
of DMRS port groups, or another preset order, or a network-configured order) from
a data bit sequence included in a CBG corresponding to each DMRS port group. Optionally,
quantities of bits extracted from data bit sequences included in CBGs corresponding
to different DMRS port groups may be the same or different, in other words, preset
quantities corresponding to different DMRS port groups may be the same or different.
For details, refer to Qi in the following part. It is assumed that extraction on the
data bit sequence included in the CBG corresponding to each DMRS port group is not
completed at a time. (2) Next, front data bits of a preset quantity are sequentially
extracted in the second preset order from a remaining data bit sequence included in
the CBG corresponding to each DMRS port group (the remaining data bit sequence included
in the CBG corresponding to each DMRS port group includes a data bit that remains
after the front data bits of the preset quantity are extracted the first time from
the data bit sequence included in the CBG corresponding to the DMRS port group), and
so on, until the entire data bit sequence included in the CBG corresponding to each
DMRS port group is extracted, that is, an order in which data bits are extracted a
plurality of times in the second preset order in the second implementation is the
first preset order, and then serial concatenation is sequentially performed on the
extracted data bits in a sequential order to obtain the concatenated data bit sequence.
Certainly, that a preset quantity of data bits are sequentially extracted in a first
preset order from a data bit sequence included in a CBG corresponding to each DMRS
port group, and serial concatenation is performed on the data bits to obtain a concatenated
data bit sequence may be alternatively implemented in another implementation. This
is not limited in this embodiment of this application.
[0109] Optionally, this embodiment of this application describes in detail the second implementation
of that "a preset quantity of data bits are sequentially extracted in a first preset
order from a data bit sequence included in a CBG corresponding to each DMRS port group,
and serial concatenation is performed on the data bits to obtain a concatenated data
bit sequence". Optionally, that a preset quantity of data bits are sequentially extracted
in a first preset order from a data bit sequence included in a CBG corresponding to
each DMRS port group, and serial concatenation is performed on the data bits to obtain
a concatenated data bit sequence includes:
when extraction is performed m times on the data bit sequence included in the CBG
corresponding to each DMRS port group to extract the entire data bit sequence, serial
concatenation is sequentially performed on a first data bit sequence to an mth data bit sequence to obtain the concatenated data bit sequence, where m is a total
quantity of times of performing extraction on the data bit sequence included in the
CBG corresponding to each DMRS port group, and m is a positive integer greater than
or equal to 2, where
the first data bit sequence is a data bit sequence obtained by sequentially extracting
first Qi data bits in a second preset order from the data bit sequence included in
the CBG corresponding to each DMRS port group and performing serial concatenation
on the first Qi data bits, where Qi represents a quantity of data bits extracted from
a data bit sequence included in a CBG corresponding to an ith DMRS port group, 1≤i≤R, i is a positive integer, R is the quantity of the DMRS port
groups, R is a positive integer greater than or equal to 2,

, Li is a quantity of transport layers corresponding to the ith DMRS port group, and ql is a modulation order corresponding to an lth transport layer; and
a kth data bit sequence is a data bit sequence obtained by sequentially extracting first
Qi data bits in the second preset order from a remaining data bit sequence included
in the CBG corresponding to each DMRS port group and performing serial concatenation
on the first Qi data bits, where 2≤k≤m, and the remaining data bit sequence included
in the CBG corresponding to the DMRS port group includes a data bit that remains after
data bit extraction is performed k-1 times on the data bit sequence included in the
CBG corresponding to the DMRS port group.
[0110] In this embodiment of this application, (1) the first Qi data bits are sequentially
extracted in the second preset order (for example, the ascending order of sequence
numbers of DMRS port groups, or the descending order of sequence numbers of DMRS port
groups, or the another preset order, or the network-configured order) from the data
bit sequence included in the CBG corresponding to each DMRS port group, and serial
concatenation is performed on the data bits to obtain the first data bit sequence.
For example, assuming that the second preset order is the ascending order of sequence
numbers of DMRS port groups, Q1 represents a quantity of data bits extracted from
a data bit sequence included in a CBG corresponding to a DMRS port group 1, Q2 represents
a quantity of data bits extracted from a data bit sequence included in a CBG corresponding
to a DMRS port group 2, and so on, where

,
L1 is a quantity of transport layers corresponding to the DMRS port group 1, and
ql is a modulation order corresponding to an
lth transport layer in transport layers corresponding to the DMRS port group 1. Optionally,
when a modulation scheme corresponding to a transport layer is quadrature phase shift
keying (Quadrature Phase Shift Keying, QPSK) modulation, a modulation order corresponding
to the transport layer is 2; when a modulation scheme corresponding to a transport
layer is 16 quadrature amplitude modulation (Quadrature Amplitude Modulation, QAM),
a modulation order corresponding to the transport layer is 4; when a modulation scheme
corresponding to a transport layer is 64QAM, a modulation order corresponding to the
transport layer is 6; or when a modulation scheme corresponding to a transport layer
is 256QAM, a modulation order corresponding to the transport layer is 8. Optionally,
for one codeword, all transport layers are corresponding to a same modulation scheme.
[0111] (2) If after extraction is performed once on the data bit sequence included in the
CBG corresponding to each DMRS port group, the entire data bit sequence is still not
extracted, first Qi data bits are sequentially extracted in the second preset order
from a remaining data bit sequence included in the CBG corresponding to each DMRS
port group, and serial concatenation is performed on the data bits to obtain a second
data bit sequence. The remaining data bit sequence included in the CBG corresponding
to each DMRS port group includes a data bit that remains after data bit extraction
is performed once on the data bit sequence included in the CBG corresponding to the
DMRS port group.
[0112] (3) If after extraction is performed twice on the data bit sequence included in the
CBG corresponding to each DMRS port group, the entire data bit sequence is still not
extracted, first Qi data bits are sequentially extracted in the second preset order
from a remaining data bit sequence included in the CBG corresponding to each DMRS
port group, and serial concatenation is performed on the data bits to obtain a third
data bit sequence, where the remaining data bit sequence included in the CBG corresponding
to each DMRS port group includes a data bit that remains after extraction is performed
twice on the data bit sequence included in the CBG corresponding to the DMRS port
group; and so on, until the whole data bit sequence included in the CBG corresponding
to each DMRS port group is extracted after first Qi data bits are sequentially extracted
in the second preset order from a remaining data bit sequence (including a data bit
that remains after data bit extraction is performed m-1 times on the data bit sequence
included in the CBG corresponding to the DMRS port group) included in the CBG corresponding
to each DMRS port group and serial concatenation is performed on the data bits. Then
serial concatenation is sequentially performed on the first data bit sequence to the
m
th data bit sequence to obtain the concatenated data bit sequence.
[0113] Optionally, an s
th data bit in the concatenated data bit sequence obtained by sequentially extracting
the preset quantity of data bits in the first preset order from the data bit sequence
included in the CBG corresponding to each DMRS port group and performing serial concatenation
on the data bits is corresponding to an (
ƒs×Qs+
as)
th data bit of a
qsth CBG, to ensure that the data bits included in the CBG corresponding to each DMRS
port group can be mapped to a transport layer corresponding to the DMRS port group
in a sequential order, and further enable an interference cancellation receiver to
cancel interference between different transport layers. 1≤s≤a total quantity of data
bits included in the CBG corresponding to each DMRS port groups. Qs represents a quantity
of data bits extracted from a data bit sequence included in a CBG corresponding to
an s
th DMRS port group.

, where └┘ represents a round-down operation.

, where Qt represents a quantity of data bits extracted from a data bit sequence included
in a CBG corresponding to a t
th DMRS port group,

, and Q0 = 0.
[0114] Further, in this embodiment of this application, optionally, when that a preset quantity
of data bits are sequentially extracted in a first preset order from a data bit sequence
included in a CBG corresponding to each DMRS port group, and serial concatenation
is performed on the data bits to obtain a concatenated data bit sequence is implemented
in the first implementation, the concatenated data bit sequence is mapped to each
transport layer according to a predefined mapping policy (for example, interleaved
mapping), to ensure that the CBG corresponding to each DMRS port group is mapped to
a transport layer corresponding to the DMRS port group. For example, all data bits
included in a CBG corresponding to a DMRS port group 1 are mapped to a transport layer
(optionally, there may be one or more layers) corresponding to the DMRS port group
1, and all data bits included in a CBG corresponding to a DMRS port group 2 are mapped
to a transport layer corresponding to the DMRS port group 2. Optionally, when that
a preset quantity of data bits are sequentially extracted in a first preset order
from a data bit sequence included in a CBG corresponding to each DMRS port group,
and serial concatenation is performed on the data bits to obtain a concatenated data
bit sequence is implemented in the second implementation, the concatenated data bit
sequence is mapped to each transport layer according to a predefined mapping policy
(for example, sequential mapping), to ensure that the CBG corresponding to each DMRS
port group is mapped to a transport layer corresponding to the DMRS port group. Certainly,
when that a preset quantity of data bits are sequentially extracted in a first preset
order from a data bit sequence included in a CBG corresponding to each DMRS port group,
and serial concatenation is performed on the data bits to obtain a concatenated data
bit sequence is implemented in another implementation, the concatenated data bit sequence
is mapped to each transport layer according to a corresponding predefined mapping
policy, to ensure that the CBG corresponding to each DMRS port group is mapped to
a transport layer corresponding to the DMRS port group. This is not limited in this
embodiment of this application.
[0115] Optionally, that the concatenated data bit sequence is mapped to each transport layer
according to a predefined mapping policy may include the following processing process.
For example, at least one of processes such as time-domain interleaving, frequency-domain
interleaving, time-frequency interleaving, scrambling, modulation, and layer mapping
is performed on the concatenated data bit sequence. Certainly, another processing
process may be further included. This is not limited in this embodiment of this application.
[0116] Certainly, that each of the at least one CBG is mapped to a transport layer corresponding
to the one DMRS port group may be alternatively implemented in another implementation.
This is not limited in this embodiment of this application.
[0117] Optionally, in this embodiment of this application, considering that a mapping relationship
between a DMRS port group and a corresponding transport layer is predefined in the
network device and/or the terminal device, or the network device and/or the terminal
device dynamically learns of a mapping relationship between a DMRS port group and
a corresponding transport layer by using a higher layer message or a physical layer
message,
Li (that is, a quantity of transport layers corresponding to each DMRS port group) in
the foregoing embodiment may be determined based on a mapping relationship between
each DMRS port group and a corresponding transport layer. Optionally,
Li in the foregoing embodiment may be alternatively indicated by using DCI. Certainly,
the quantity of transport layers corresponding to each DMRS port group may be alternatively
indicated in another manner. This is not limited in this embodiment of this application.
[0118] Optionally, for that the quantity of transport layers corresponding to each DMRS
port group is indicated by using DCI, there may be at least the following several
indication manners: (1) A total quantity of transport layers, and a quantity of transport
layers corresponding to each remaining DMRS port group other than any one of all DMRS
port groups are indicated by using DCI. For example, assuming that there are a total
of two DMRS port groups, a total quantity of the transport layers, and a quantity
of transport layers corresponding to any one of the two DMRS port groups are indicated
by using DCI. (2) A quantity of transport layers corresponding to each DMRS port group
is indicated by using DCI. (3) A quantity of transport layers corresponding to each
DMRS port group is indicated by performing joint coding on a bit in an antenna port
indication field in DCI. For example, indication is performed in a manner of reusing
a bit in the antenna port indication field in the DCI or adding a bit to the antenna
port indication field in the DCI.
[0119] In this embodiment of this application, to ensure that extraction of the data bit
sequences included in the CBGs corresponding to all the DMRS port groups is simultaneously
completed, it is pre-stipulated that lengths of the data bit sequences included in
the CBGs corresponding to all the DMRS port groups are the same. Alternatively, optionally,
CBGs corresponding to some DMRS port groups are filled with placeholders. A CBG that
is corresponding to a DMRS port group (referred to as a j
th DMRS port group in the following embodiment, where 1≤j≤R) and that needs to be filled
with a placeholder satisfies the following feature: A quantity C0 of times required
for extracting an entire data bit sequence included in the CBG corresponding to the
j
th DMRS port group is less than a quantity Cmax of times required for extracting an
entire data bit sequence included in a CBG corresponding to a p
th DMRS port group. The quantity Cmax of times required for extracting the entire data
bit sequence included in the CBG corresponding to the p
th DMRS port group is a maximum quantity of times in quantities of times required for
extracting all entire data bit sequences included in the CBGs corresponding to all
the DMRS port groups, where 1≤p≤R. Optionally, a quantity of placeholders that need
to be filled in the CBG corresponding to the j
th DMRS port group is Qj×(Cmax-C0).
[0120] Optionally, when data communication in this embodiment of this application is uplink
data transmission, operations, such as "extraction" and "mapping", included in this
embodiment of this application are performed by the terminal device. When data communication
in this embodiment of this application is downlink data transmission, operations,
such as "extraction" and "mapping", included in this embodiment of this application
are performed by the network device.
[0121] In this embodiment of this application, the network device and the terminal device
perform data communication, where the data is corresponding to the transport block,
the transport block is divided into the at least one code block group CBG, and each
of the at least one CBG is corresponding to one DMRS port group. The preset quantity
of data bits are sequentially extracted in the first preset order from the data bit
sequence included in the CBG corresponding to each DMRS port group, and serial concatenation
is performed on the data bits to obtain the concatenated data bit sequence. In addition,
the concatenated data bit sequence is mapped to each transport layer according to
the predefined mapping policy, to ensure that the CBG corresponding to each DMRS port
group is mapped to a transport layer corresponding to the DMRS port group. It can
be learned that, it is ensured that data flows sent through different DMRS port groups
belong to different CBGs, so that a receive end can independently decode a CBG corresponding
to each DMRS port group (in other words, can independently decode data flows mapped
to different transport layers), and therefore can support interference cancellation
performed by an interference cancellation receiver.
[0122] Optionally, the foregoing embodiment of this application mainly describes a process
of mapping, to a corresponding transport layer, a CBG obtained through division in
space domain (for example, a transport layer or an antenna port), and imposes no limitation
or requirement on mapping of a CBG obtained through division in time domain or frequency
domain. If division in time domain and/or frequency domain are/is further used, this
embodiment of this application is also applicable to a CBG obtained through transport
block division in space domain in combination with symbol division in time domain
and/or subband division in frequency domain, and certainly, is also applicable to
other cases. This is not limited in this embodiment of this application. For example,
for mapping, to a corresponding physical resource, a CBG obtained through division
in space domain in combination with division in time domain and/or frequency domain,
CBGs mapped to a same time-domain symbol and/or frequency-domain subband may be mapped
according to the process, described in the foregoing embodiment of this application,
of mapping a CBG to a corresponding transport layer (that is, space-domain mapping).
[0123] It should be noted that same or similar concepts or processes may be cited or combined
in the foregoing different embodiments, and division of the different embodiments
is merely intended to describe this application more clearly.
[0124] Optionally, the process of mapping a CBG to a corresponding transport layer in Embodiment
4 to Embodiment 6 of this application may be alternatively replaced with the mapping
process in Embodiment 7 of this application (this is equivalent to replacing a DMRS
port group with a transport layer group corresponding to each CBG, where the transport
layer group is a set of transport layers to which the CBG is mapped). For the specific
mapping process, refer to corresponding content in Embodiment 7 of this application.
Details are not described herein again.
[0125] Optionally, Embodiment 7 of the data communication method in this application may
be alternatively performed independently from any one of Embodiment 1 to Embodiment
6, without depending on the other embodiments. For example, the implementations, described
in Embodiment 7 of the data communication method in this application, about mapping
a CBG to a corresponding transport layer may also be applied to other data communication
processes. This is not limited in this embodiment of this application.
[0126] FIG. 8 is a schematic structural diagram of Embodiment 1 of a network device according
to this application. As shown in FIG. 8, the network device 80 provided in this embodiment
includes a determining module 801 and a communication module 802.
[0127] The determining module 801 is configured to determine demodulation reference signal
DMRS port groups, where a quantity of the DMRS port groups is greater than or equal
to 2.
[0128] The communication module 802 is configured to communicate data with a terminal device,
where the data is corresponding to a transport block, the transport block is divided
into at least one code block group CBG, and each of the at least one CBG is corresponding
to one DMRS port group and is mapped to a transport layer corresponding to the one
DMRS port group. Optionally, that the transport block is divided into at least one
CBG includes:
the transport block is divided into N code blocks CBs, where N = ┌B / c┐, B represents a total quantity of bits of the transport block with an added redundancy
check bit, C represents a preset value, and ┌ ┐ represents a round-up operation; and
the N CBs are grouped into CBGs corresponding to the DMRS port groups. Optionally,
a quantity of CBs included in each CBG is equal to a value calculated based on the
following formula: └(B0 / Bs) × N┘ or ┌(B0 / Bs) × N┐, where
Bo represents a quantity of bits of data sent through a DMRS port group corresponding
to the CBG, Bs represents a total quantity of bits of data sent through the DMRS port groups, └
┘ represents a round-down operation, and ┌ ┐ represents a round-up operation.
[0129] Optionally, that the transport block is divided into at least one CBG includes:
the transport block is divided into a transport sub-block corresponding to each DMRS
port group; and
each transport sub-block is encoded to obtain a CBG corresponding to the DMRS port
group.
[0130] Optionally, the network device further includes:
a notification module, configured to send a notification message to the terminal device,
where the notification message carries configuration information of the DMRS port
groups.
[0131] Optionally, that each of the at least one CBG is mapped to a transport layer corresponding
to the one DMRS port group includes:
a preset quantity of data bits are sequentially extracted in a first preset order
from a data bit sequence included in a CBG corresponding to each DMRS port group,
and serial concatenation is performed on the data bits to obtain a concatenated data
bit sequence; and
the concatenated data bit sequence is mapped to each transport layer according to
a predefined mapping policy.
[0132] Optionally, that a preset quantity of data bits are sequentially extracted in a first
preset order from a data bit sequence included in a CBG corresponding to each DMRS
port group, and serial concatenation is performed on the data bits to obtain a concatenated
data bit sequence includes:
when extraction is performed m times on the data bit sequence included in the CBG
corresponding to each DMRS port group to extract the entire data bit sequence, serial
concatenation is sequentially performed on a first data bit sequence to an mth data bit sequence to obtain the concatenated data bit sequence, where m is a total
quantity of times of performing extraction on the data bit sequence included in the
CBG corresponding to each DMRS port group, and m is a positive integer greater than
or equal to 2, where
the first data bit sequence is a data bit sequence obtained by sequentially extracting
first Qi data bits in a second preset order from the data bit sequence included in
the CBG corresponding to each DMRS port group and performing serial concatenation
on the first Qi data bits, where Qi represents a quantity of data bits extracted from
a data bit sequence included in a CBG corresponding to an ith DMRS port group, 1≤i≤R, i is a positive integer, R is the quantity of the DMRS port
groups, R is a positive integer greater than or equal to 2,

, Li is a quantity of transport layers corresponding to the ith DMRS port group, and ql is a modulation order corresponding to an lth transport layer; and
a kth data bit sequence is a data bit sequence obtained by sequentially extracting first
Qi data bits in the second preset order from a remaining data bit sequence included
in the CBG corresponding to each DMRS port group and performing serial concatenation
on the first Qi data bits, where 2≤k≤m, and the remaining data bit sequence included
in the CBG corresponding to the DMRS port group includes a data bit that remains after
data bit extraction is performed k-1 times on the data bit sequence included in the
CBG corresponding to the DMRS port group.
[0133] The network device in this embodiment may be configured to perform the technical
solution in any one of Embodiment 1 to Embodiment 3, or Embodiment 7 of the data communication
method in this application. Implementation principles and technical effects thereof
are similar. Details are not described herein again.
[0134] FIG. 9 is a schematic structural diagram of Embodiment 2 of a network device according
to this application. As shown in FIG. 9, the network device 90 provided in this embodiment
includes a memory 901, a processor 902, a transceiver 903, and at least one communications
bus 904.
[0135] The communications bus 904 is configured to implement a communications connection
between elements. The memory 901 may include a high-speed RAM, or may include a nonvolatile
memory NVM, for example, at least one magnetic disk memory. The memory 901 may store
various programs used to perform various processing functions and implement the method
steps in the foregoing embodiments of this application. The transceiver 903 may be
a corresponding input/output interface with a communication function. The processor
902 is configured to invoke a program instruction in the memory 901 to perform the
following step: determining demodulation reference signal DMRS port groups, where
a quantity of the DMRS port groups is greater than or equal to 2. The transceiver
903 is configured to communicate data with a terminal device, where the data is corresponding
to a transport block, the transport block is divided into at least one code block
group CBG, and each of the at least one CBG is corresponding to one DMRS port group
and is mapped to a transport layer corresponding to the one DMRS port group.
[0136] Optionally, that the transport block is divided into at least one CBG includes:
the transport block is divided into N code blocks CBs, where N = ┌B / c┐, B represents a total quantity of bits of the transport block with an added redundancy
check bit, c represents a preset value, and ┌ ┐ represents a round-up operation; and
the N CBs are grouped into CBGs corresponding to the DMRS port groups. Optionally,
a quantity of CBs included in each CBG is equal to a value calculated based on the
following formula: └(B0 / Bs)×N┘ or ┌(B0 / Bs) × N┐, where
Bo represents a quantity of bits of data sent through a DMRS port group corresponding
to the CBG, Bs represents a total quantity of bits of data sent through the DMRS port groups, └
┘ represents a round-down operation, and ┌ ┐ represents a round-up operation.
[0137] Optionally, that the transport block is divided into at least one CBG includes:
the transport block is divided into a transport sub-block corresponding to each DMRS
port group; and
each transport sub-block is encoded to obtain a CBG corresponding to the DMRS port
group.
[0138] Optionally, the transceiver 903 is further configured to send a notification message
to the terminal device, where the notification message carries configuration information
of the DMRS port groups.
[0139] Optionally, that each of the at least one CBG is mapped to a transport layer corresponding
to the one DMRS port group includes:
a preset quantity of data bits are sequentially extracted in a first preset order
from a data bit sequence included in a CBG corresponding to each DMRS port group,
and serial concatenation is performed on the data bits to obtain a concatenated data
bit sequence; and
the concatenated data bit sequence is mapped to each transport layer according to
a predefined mapping policy.
[0140] Optionally, that a preset quantity of data bits are sequentially extracted in a first
preset order from a data bit sequence included in a CBG corresponding to each DMRS
port group, and serial concatenation is performed on the data bits to obtain a concatenated
data bit sequence includes:
when extraction is performed m times on the data bit sequence included in the CBG
corresponding to each DMRS port group to extract the entire data bit sequence, serial
concatenation is sequentially performed on a first data bit sequence to an mth data bit sequence to obtain the concatenated data bit sequence, where m is a total
quantity of times of performing extraction on the data bit sequence included in the
CBG corresponding to each DMRS port group, and m is a positive integer greater than
or equal to 2, where
the first data bit sequence is a data bit sequence obtained by sequentially extracting
first Qi data bits in a second preset order from the data bit sequence included in
the CBG corresponding to each DMRS port group and performing serial concatenation
on the first Qi data bits, where Qi represents a quantity of data bits extracted from
a data bit sequence included in a CBG corresponding to an ith DMRS port group, 1≤i≤R, i is a positive integer, R is the quantity of the DMRS port
groups, R is a positive integer greater than or equal to 2,

, Li is a quantity of transport layers corresponding to the ith DMRS port group, and ql is a modulation order corresponding to an lth transport layer; and
a kth data bit sequence is a data bit sequence obtained by sequentially extracting first
Qi data bits in the second preset order from a remaining data bit sequence included
in the CBG corresponding to each DMRS port group and performing serial concatenation
on the first Qi data bits, where 2≤k≤m, and the remaining data bit sequence included
in the CBG corresponding to the DMRS port group includes a data bit that remains after
data bit extraction is performed k-1 times on the data bit sequence included in the
CBG corresponding to the DMRS port group.
[0141] The network device in this embodiment may be configured to perform the technical
solution in any one of Embodiment 1 to Embodiment 3, or Embodiment 7 of the data communication
method in this application. Implementation principles and technical effects thereof
are similar. Details are not described herein again.
[0142] FIG. 10 is a schematic structural diagram of Embodiment 1 of a terminal device according
to this application. As shown in FIG. 10, the terminal device 100 provided in this
embodiment includes an obtaining module 1001 and a communication module 1002.
[0143] The obtaining module 1001 is configured to obtain configuration information of demodulation
reference signal DMRS port groups, where a quantity of the DMRS port groups is greater
than or equal to 2.
[0144] The communication module 1002 is configured to communicate data with a network device,
where the data is corresponding to a transport block, the transport block is divided
into at least one code block group CBG, and each of the at least one CBG is corresponding
to one DMRS port group and is mapped to a transport layer corresponding to the one
DMRS port group. Optionally, that the transport block is divided into at least one
CBG includes:
the transport block is divided into N code blocks CBs, where N = ┌B / c┐, B represents a total quantity of bits of the transport block with an added redundancy
check bit, C represents a preset value, and ┌ ┐ represents a round-up operation; and
the N CBs are grouped into CBGs corresponding to the DMRS port groups. Optionally,
a quantity of CBs included in each CBG is equal to a value calculated based on the
following formula: └(B0 / Bs) × N┘ or ┌(B0 / Bs) × N┐, where
Bo represents a quantity of bits of data sent through a DMRS port group corresponding
to the CBG, Bs represents a total quantity of bits of data sent through the DMRS port groups, └
┘ represents a round-down operation, and ┌ ┐ represents a round-up operation.
[0145] Optionally, that the transport block is divided into at least one CBG includes:
the transport block is divided into a transport sub-block corresponding to each DMRS
port group; and
each transport sub-block is encoded to obtain a CBG corresponding to the DMRS port
group.
[0146] Optionally, the obtaining module is specifically configured to receive a notification
message sent by the network device, where the notification message carries the configuration
information of the DMRS port groups.
[0147] Optionally, that each of the at least one CBG is mapped to a transport layer corresponding
to the one DMRS port group includes:
a preset quantity of data bits are sequentially extracted in a first preset order
from a data bit sequence included in a CBG corresponding to each DMRS port group,
and serial concatenation is performed on the data bits to obtain a concatenated data
bit sequence; and
the concatenated data bit sequence is mapped to each transport layer according to
a predefined mapping policy.
[0148] Optionally, that a preset quantity of data bits are sequentially extracted in a first
preset order from a data bit sequence included in a CBG corresponding to each DMRS
port group, and serial concatenation is performed on the data bits to obtain a concatenated
data bit sequence includes:
when extraction is performed m times on the data bit sequence included in the CBG
corresponding to each DMRS port group to extract the entire data bit sequence, serial
concatenation is sequentially performed on a first data bit sequence to an mth data bit sequence to obtain the concatenated data bit sequence, where m is a total
quantity of times of performing extraction on the data bit sequence included in the
CBG corresponding to each DMRS port group, and m is a positive integer greater than
or equal to 2, where
the first data bit sequence is a data bit sequence obtained by sequentially extracting
first Qi data bits in a second preset order from the data bit sequence included in
the CBG corresponding to each DMRS port group and performing serial concatenation
on the first Qi data bits, where Qi represents a quantity of data bits extracted from
a data bit sequence included in a CBG corresponding to an ith DMRS port group, 1≤i≤R, i is a positive integer, R is the quantity of the DMRS port
groups, R is a positive integer greater than or equal to 2,

, Li is a quantity of transport layers corresponding to the ith DMRS port group, and ql is a modulation order corresponding to an lth transport layer; and
a kth data bit sequence is a data bit sequence obtained by sequentially extracting first
Qi data bits in the second preset order from a remaining data bit sequence included
in the CBG corresponding to each DMRS port group and performing serial concatenation
on the first Qi data bits, where 2≤k≤m, and the remaining data bit sequence included
in the CBG corresponding to the DMRS port group includes a data bit that remains after
data bit extraction is performed k-1 times on the data bit sequence included in the
CBG corresponding to the DMRS port group.
[0149] The terminal device in this embodiment may be configured to perform the technical
solution in any one of Embodiment 1 to Embodiment 3, or Embodiment 7 of the data communication
method in this application. Implementation principles and technical effects thereof
are similar. Details are not described herein again.
[0150] FIG. 11 is a schematic structural diagram of Embodiment 2 of a terminal device according
to this application. As shown in FIG. 11, the terminal device 110 provided in this
embodiment includes a memory 1101, a processor 1102, a transceiver 1103, and at least
one communications bus 1104.
[0151] The communications bus 1104 is configured to implement a communications connection
between elements. The memory 1101 may include a high-speed RAM, or may include a nonvolatile
memory NVM, for example, at least one magnetic disk memory. The memory 1101 may store
various programs used to perform various processing functions and implement the method
steps in the foregoing embodiments of this application. The transceiver 1103 may be
a corresponding input/output interface with a communication function. The processor
1102 is configured to invoke a program instruction in the memory 1101 to perform the
following step: obtaining configuration information of demodulation reference signal
DMRS port groups, where a quantity of the DMRS port groups is greater than or equal
to 2. The transceiver 1103 is configured to communicate data with a network device,
where the data is corresponding to a transport block, the transport block is divided
into at least one code block group CBG, and each of the at least one CBG is corresponding
to one DMRS port group and is mapped to a transport layer corresponding to the one
DMRS port group.
[0152] Optionally, that the transport block is divided into at least one CBG includes:
the transport block is divided into N code blocks CBs, where N = ┌B / c┐, B represents a total quantity of bits of the transport block with an added redundancy
check bit, C represents a preset value, and ┌ ┐ represents a round-up operation; and
the N CBs are grouped into CBGs corresponding to the DMRS port groups. Optionally,
a quantity of CBs included in each CBG is equal to a value calculated based on the
following formula: └(B0 / Bs) × N┘ or ┌(B0 / Bs) × N┐, where
Bo represents a quantity of bits of data sent through a DMRS port group corresponding
to the CBG, Bs represents a total quantity of bits of data sent through the DMRS port groups, └
┘ represents a round-down operation, and ┌ ┐ represents a round-up operation.
[0153] Optionally, that the transport block is divided into at least one CBG includes:
the transport block is divided into a transport sub-block corresponding to each DMRS
port group; and
each transport sub-block is encoded to obtain a CBG corresponding to the DMRS port
group.
[0154] Optionally, the transceiver is further configured to receive a notification message
sent by the network device, where the notification message carries the configuration
information of the DMRS port groups. Correspondingly, the processor is further configured
to obtain the configuration information of the DMRS port groups based on the notification
message. Optionally, that each of the at least one CBG is mapped to a transport layer
corresponding to the one DMRS port group includes:
a preset quantity of data bits are sequentially extracted in a first preset order
from a data bit sequence included in a CBG corresponding to each DMRS port group,
and serial concatenation is performed on the data bits to obtain a concatenated data
bit sequence; and
the concatenated data bit sequence is mapped to each transport layer according to
a predefined mapping policy.
[0155] Optionally, that a preset quantity of data bits are sequentially extracted in a first
preset order from a data bit sequence included in a CBG corresponding to each DMRS
port group, and serial concatenation is performed on the data bits to obtain a concatenated
data bit sequence includes:
when extraction is performed m times on the data bit sequence included in the CBG
corresponding to each DMRS port group to extract the entire data bit sequence, serial
concatenation is sequentially performed on a first data bit sequence to an mth data bit sequence to obtain the concatenated data bit sequence, where m is a total
quantity of times of performing extraction on the data bit sequence included in the
CBG corresponding to each DMRS port group, and m is a positive integer greater than
or equal to 2, where
the first data bit sequence is a data bit sequence obtained by sequentially extracting
first Qi data bits in a second preset order from the data bit sequence included in
the CBG corresponding to each DMRS port group and performing serial concatenation
on the first Qi data bits, where Qi represents a quantity of data bits extracted from
a data bit sequence included in a CBG corresponding to an ith DMRS port group, 1≤i≤R, i is a positive integer, R is the quantity of the DMRS port
groups, R is a positive integer greater than or equal to 2,

, Li is a quantity of transport layers corresponding to the ith DMRS port group, and ql is a modulation order corresponding to an lth transport layer; and
a kth data bit sequence is a data bit sequence obtained by sequentially extracting first
Qi data bits in the second preset order from a remaining data bit sequence included
in the CBG corresponding to each DMRS port group and performing serial concatenation
on the first Qi data bits, where 2≤k≤m, and the remaining data bit sequence included
in the CBG corresponding to the DMRS port group includes a data bit that remains after
data bit extraction is performed k-1 times on the data bit sequence included in the
CBG corresponding to the DMRS port group.
[0156] The terminal device in this embodiment may be configured to perform the technical
solution in any one of Embodiment 1 to Embodiment 3, or Embodiment 7 of the data communication
method in this application. Implementation principles and technical effects thereof
are similar. Details are not described herein again.
[0157] In Embodiment 3 of a network device in this application, the network device includes
a determining module and a communication module. Optionally, for a schematic structural
diagram of the network device, refer to FIG. 8.
[0158] The determining module is configured to determine a quantity of transport layers.
[0159] The communication module is configured to communicate data with a terminal device,
where the data is corresponding to a transport block, and the transport block is mapped
to a corresponding transport layer based on the quantity of transport layers.
[0160] Optionally, that the transport block is mapped to a corresponding transport layer
based on the quantity of transport layers includes:
if the quantity of transport layers is equal to 1 or 2, the transport block is mapped
to the corresponding transport layer; or
if the quantity of transport layers is equal to 3 or 4, the transport block is divided
into two code block groups CBGs, and the two CBGs are mapped to different transport
layers. Optionally, the network device further includes:
the determining module, configured to determine, based on that a difference between
channel quantity information corresponding to different DMRS ports is greater than
a preset threshold, to divide the transport block when the quantity of transport layers
is equal to 3 or 4.
[0161] Optionally, the network device further includes:
a sending module, configured to send a group configuration message to the terminal
device, where the group configuration message is used to instruct to divide the transport
block when the quantity of transport layers is equal to 3 or 4.
[0162] The network device in this embodiment may be configured to perform the technical
solution in any one of Embodiment 4 to Embodiment 6, or Embodiment 7 of the data communication
method in this application. Implementation principles and technical effects thereof
are similar. Details are not described herein again.
[0163] In Embodiment 4 of a network device in this application, the network device includes
a memory, a processor, a transceiver, and at least one communications bus. Optionally,
for a schematic structural diagram of the network device, refer to FIG. 9.
[0164] The communications bus is configured to implement a communications connection between
elements. The memory may include a high-speed RAM memory, or may include a nonvolatile
memory NVM, for example, at least one magnetic disk memory. The memory may store various
programs used to perform various processing functions and implement the method steps
in the foregoing embodiments of this application. The transceiver may be a corresponding
input/output interface with a communication function. The processor is configured
to invoke a program instruction in the memory to perform the following step: determining
a quantity of transport layers. The transceiver is configured to communicate data
with a terminal device, where the data is corresponding to a transport block, and
the transport block is mapped to a corresponding transport layer based on the quantity
of transport layers.
[0165] Optionally, that the transport block is mapped to a corresponding transport layer
based on the quantity of transport layers includes:
if the quantity of transport layers is equal to 1 or 2, the transport block is mapped
to the corresponding transport layer; or
if the quantity of transport layers is equal to 3 or 4, the transport block is divided
into two code block groups CBGs, and the two CBGs are mapped to different transport
layers. Optionally, the processor is further configured to determine, based on that
a difference between channel quantity information corresponding to different DMRS
ports is greater than a preset threshold, to divide the transport block when the quantity
of transport layers is equal to 3 or 4.
[0166] Optionally, the transceiver is further configured to send a group configuration message
to the terminal device, where the group configuration message is used to instruct
to divide the transport block when the quantity of transport layers is equal to 3
or 4.
[0167] The network device in this embodiment may be configured to perform the technical
solution in any one of Embodiment 4 to Embodiment 6, or Embodiment 7 of the data communication
method in this application. Implementation principles and technical effects thereof
are similar. Details are not described herein again.
[0168] In Embodiment 3 of a terminal device in this application, the terminal device includes
an obtaining module and a communication module. Optionally, for a schematic structural
diagram of the terminal device, refer to FIG. 10.
[0169] The obtaining module is configured to obtain a quantity of transport layers.
[0170] The communication module is configured to communicate data with a network device,
where the data is corresponding to a transport block, and the transport block is mapped
to a corresponding transport layer based on the quantity of transport layers.
[0171] Optionally, that the transport block is mapped to a corresponding transport layer
based on the quantity of transport layers includes:
if the quantity of transport layers is equal to 1 or 2, the transport block is mapped
to the corresponding transport layer; or
if the quantity of transport layers is equal to 3 or 4, and a group configuration
message is used to instruct to divide the transport block, the transport block is
divided into two code block groups CBGs, and the two CBGs are mapped to different
transport layers. Optionally, the terminal device further includes:
a receiving module, configured to receive the group configuration message sent by
the network device.
[0172] The terminal device in this embodiment may be configured to perform the technical
solution in any one of Embodiment 4 to Embodiment 6, or Embodiment 7 of the data communication
method in this application. Implementation principles and technical effects thereof
are similar. Details are not described herein again.
[0173] In Embodiment 4 of a terminal device in this application, the terminal device includes
a memory, a processor, a transceiver, and at least one communications bus. Optionally,
for a schematic structural diagram of the terminal device, refer to FIG. 11.
[0174] The communications bus is configured to implement a communications connection between
elements. The memory may include a high-speed RAM, or may include a nonvolatile memory
NVM, for example, at least one magnetic disk memory. The memory may store various
programs used to perform various processing functions and implement the method steps
in the foregoing embodiments of this application. The transceiver may be a corresponding
input/output interface with a communication function. The processor is configured
to invoke a program instruction in the memory to perform the following step: obtaining
a quantity of transport layers. The transceiver is configured to communicate data
with a network device, where the data is corresponding to a transport block, and the
transport block is mapped to a corresponding transport layer based on the quantity
of transport layers.
[0175] Optionally, that the transport block is mapped to a corresponding transport layer
based on the quantity of transport layers includes:
if the quantity of transport layers is equal to 1 or 2, the transport block is mapped
to the corresponding transport layer; or
if the quantity of transport layers is equal to 3 or 4, and a group configuration
message is used to instruct to divide the transport block, the transport block is
divided into two code block groups CBGs, and the two CBGs are mapped to different
transport layers. Optionally, the transceiver is further configured to receive the
group configuration message sent by the network device.
[0176] The terminal device in this embodiment may be configured to perform the technical
solution in any one of Embodiment 4 to Embodiment 6, or Embodiment 7 of the data communication
method in this application. Implementation principles and technical effects thereof
are similar. Details are not described herein again.
[0177] It can be clearly understood by a person skilled in the art that, for convenience
and brevity of description, division of the foregoing function modules is merely used
as an example for description. In actual application, the foregoing functions may
be allocated to different function modules and implemented according to a requirement,
that is, an inner structure of an apparatus is divided into different function modules
to implement all or some of the functions described above. For a detailed working
process of the foregoing apparatuses, refer to a corresponding process in the foregoing
method embodiments, and details are not described herein again.
[0178] In the several embodiments provided in this application, it should be understood
that the disclosed apparatuses and methods may be implemented in other manners. For
example, the described apparatus embodiments are merely examples. For example, the
unit division is merely logical function division and may be other division in actual
implementation. For example, a plurality of units or components may be combined or
integrated into another system, or some features may be ignored or not performed.
In addition, the shown or discussed mutual couplings or direct couplings or communication
connections may be implemented by using some interfaces. The indirect couplings or
communication connections between the apparatuses or units may be implemented in electrical,
mechanical, or other forms.
[0179] The units described as separate parts may or may not be physically separated, and
parts shown as units may or may not be physical units, may be located in one position,
or may be distributed on a plurality of network units. Some or all of the units may
be selected according to actual requirements to achieve the objectives of the solutions
of the embodiments.
[0180] In addition, functional units in the embodiments of this application may be integrated
into one processing unit, or each of the units may exist alone physically, or two
or more units may be integrated into one unit. The integrated unit may be implemented
in a form of hardware, or may be implemented in a form of hardware in addition to
a software functional unit.
[0181] All or some of the foregoing embodiments may be implemented by using software, hardware,
firmware, or any combination thereof. When software is used to implement the embodiments,
the embodiments may be implemented completely or partially in a form of a computer
program product. The computer program product includes one or more computer instructions.
When the computer program instructions are loaded and executed on a computer, all
or some of the procedures or functions according to the embodiments of the present
invention are generated. The computer may be a general purpose computer, a dedicated
computer, a computer network, or another programmable apparatus. The computer instructions
may be stored in a computer readable storage medium or may be transmitted from a computer
readable storage medium to another computer readable storage medium. For example,
the computer instructions may be transmitted from a web site, computer, server, or
data center to another web site, computer, server, or data center in a wired (for
example, a coaxial cable, an optical fiber, or a digital subscriber line (DSL)) or
wireless (for example, infrared, radio, or microwave) manner. The computer readable
storage medium may be any usable medium accessible to a computer, or a data storage
device, such as a server or a data center, integrating one or more usable media. The
usable medium may be a magnetic medium (for example, a floppy disk, a hard disk, or
a magnetic tape), an optical medium (for example, a DVD), a semiconductor medium (for
example, a solid state disk (SSD)), or the like.